The United States was the first country to call for a regularly held census. The Constitution required that a census of all "Persons...excluding Indians not taxed" be performed to determine the collection of taxes and the appropriation of seats in the House of Representatives. The first nine censuses from 1790-1870 were organized under the United States Federal Court system. Each district was assigned a U.S. marshal who hired other marshals to administer the census. Governors were responsible for enumeration in territories.
The jurisdiction of the original thirteen states canvassed an area of seventeen present states. Schedules survive for eleven of the thirteen original states: Connecticut, Maine (part of Massachusetts at the time), Maryland, Massachusetts, New Hampshire, New York, North Carolina, Pennsylvania, Rhode Island, South Carolina, and Vermont. (Vermont became the fourteenth state early in 1791 and was included in the census schedules).
Enumerators were only required to make one copy of the census schedules to be held by the clerk of the district court in their respective area. In 1830, Congress passed a law requiring the return of all decennial censuses from 1790-1830. At this point it was discovered that many of the 1790 schedules had been lost or destroyed. Thus, we have about two-thirds of the original census from the time period. The 1790 census suffered district losses of Delaware, Georgia, Kentucky, New Jersey, and Virginia. However, some of the schedules for these states have been re-created using tax lists and other records. Virginia was eventually reconstructed from tax lists as well as some counties from North Carolina and Maryland.

Taken from Chapter 5: Research in Census Records, The Source: A Guidebook of American Genealogy by Loretto Dennis Szucs; edited by Loretto Dennis Szucs and Sandra Hargreaves Luebking (Salt Lake City, UT: Ancestry Incorporated, 1997).